Field of the Invention
The present invention relates to a closure comprising a snap hinge serving to connect the lower part of such closure to its lid.
Closures of the above-mentioned kind are known in the art. U.S. Pat. No. 4,487,324 OSTROWSKY/SEAQUIST, for example, discloses a closure having a snap hinge whereby two film hinges, lying in the main axis of rotation, are arranged on either side of a single spring element (hereinafter called "elastic" element). In contrast, DE-GMS 87 05 035--WEENER PLASTIK discloses a closure comprising an opposite arrangement of the snap hinge, wherein two elastic elements are arranged on either side of a single film hinge.
The concept of "surrounding border" is intended to embrace borders that do not completely run around the edge of the lid.
In both of the above named patents and particularly in the U.S. patent, parts of the lower part and lid, which are connected together by means of the film hinges, project relatively far outside of the closure. This results from the fact that both lower part and lid are, when being moulded, positioned relative to each other as indicated in FIG. 5 of the U.S. patent. Since, however, the mould for the lower part and lid have a specific wall thickness, the state of the art contemplated only the need to bridge such mould wall thicknesses by means of the sections that lead from both lower part and lid to the film hinge.
The same applies to U.S. Pat. No. 3,628,215--EVERBURG/AMERICAN OPTICAL--although the bridging sections, which had to exist due to the thicknesses of the mould wall, were not shown in all of the figures.